In various commercial and industrial environments, the use of optical indicia, such as bar code symbols, has become the norm for identifying products and inventory. Typically, each item is marked with optical indicia associated with a description of the item and other attributes (for example, price) that are stored in a database of a host device or network system. Optical readers are used to read the optical indicia and provide that reading as input information to host devices. In some cases, the data is provided to the host devices via base units, which communicate with the optical reader. Examples of host devices include a computer (fixed or portable), a personal digital assistant (PDA), a portable data terminal (PDT), a point of sale (POS) terminal, a transaction terminal, cash register, or similar device. Checkout stations in retail settings typically employ stationary presentation-type optical readers, mobile hand held optical readers hardwired to a base unit, mobile wireless hand held optical readers that communicate wirelessly with a linked base unit, or some combination of the above to read optical indicia such as bar code symbols, or bar codes.
Stationary presentation-type optical readers, such as flat bed scanners, typically require a cashier to manually move an item bearing optical indicia into the field of view of the optical reader and orient the item such that the optical reader can scan the information and communicate this information to the cash register. While stationary presentation-type optical readers may be adequate for scanning encoded optical indicia on small items that are easily moved through their field of view by a cashier or other operator, these types of optical readers are not well suited for scanning large or heavy items that need to be repositioned by the cashier or customer so the scanner can read the optical indicia. This movement of large and/or heavy objects is inherently risky and undesirable. Furthermore, since stationary presentation-type optical readers require that the cashier position the item to be scanned somewhat precisely into the field of view of the optical reader so that the optical reader can scan the optical indicia, multiple attempts are often required to achieve a successful scan. This can lead to frustration by the cashier and customer and thus detract from customer satisfaction.
An advance upon the stationary presentation-type optical scanner is the use of a mobile hand held optical reader hardwired to a linked base unit. This configuration permits the cashier to manually move the hand held optical reader into position to scan an item's optical indicia, rather than having to move the item into the field of view of the optical reader as in the stationary presentation-type optical scanner. The scanned information from the optical indicia is then transmitted to the hand held optical reader's linked base unit via the hardwired connection between the two components. The base unit then communicates this information to the cash register. Alternatively, the hand held optical reader can be connected directly to the cash register. Unfortunately, this approach does not eliminate the problems associated with scanning items that are out of reach of the hardwired hand held optical reader and must be repositioned into the field of view of the optical reader so that the optical reader can scan the optical indicia. One approach to solve this access problem was to provide longer cords to the hardwired optical reader. However, the extra length must be stowed when not in use, which delays the time between scans, and may further detract from customer satisfaction.
In order to eliminate the limitations imposed by hardwiring the hand held optical reader to its base unit, another approach is the use of a wireless optical reader that can communicate wirelessly with its linked base unit. In this approach, the wireless hand held optical reader is held in a base unit or docking cradle until needed to read optical indicia that are out of the view of a stationary presentation-type optical reader. The wireless optical reader houses a battery to power the optical reader's internal electronics. The cashier can manually move the hand held optical reader into position to scan an item's optical indicia as long as the optical reader is within a distance where it can communicate wirelessly with its linked base unit. The scanned information is then transmitted to the hand held optical reader's linked base unit over the wireless connection. The base unit then communicates this bar code information to the cash register.
One noted problem with wireless mobile hand held optical readers that communicates wirelessly with its individual base unit is that the power requirements to transmit the data is substantial. Accordingly, the batteries in the hand held unit were large, heavy, and recharged very slowly. The batteries made the hand held optical reader difficult to wield, and caused wrist fatigue over the course of a working day.